Oil seal



P; WILDER Nov. 25, 1941.

OIL SEAL Filed April 28, 1939 ATTORNEYS.

enemies Nev. 2s, 1941 p on. sau.

Phelps Wilder, Chicago, Ill.,

Rawhide Manufacturing Ill., a corporation of Illinois Nr! orricaassigner to Chicago Company, Chicago,

application Apr 2s, 1939, serial No. 270,493

(ci. asasl 3Claims.

This invention has to do with oil seals of the type in which the packingis provided with an interiorly tapered sealing portion which `is pressedagainst the shaft or other member to be sealed by an endless coilspring.

The principal object of the invention is to provide an improved seal ofthe type described in which the spring is held in a groove in thepacking and the grooved portion of the packing is undercut tosubstantially the median plane of the spring to locate thesealing lip ofthe packing in the plane of greatest pressure.

Other more speciiic objects and advantages of the invention will be'apparent to those skilled in the art uponV a full understanding of theimproved sealing unit.

Several dierent embodiments of the invention are presented herein forthe purpose of exempl-ification, but it will of course be appreciatedthat the invention is susceptible of incorporation in still otherstructurally modiiied forms coming equally within the scope of theappended claims.

In the accompanying drawing:

Fig. 1 is a diametrical section through-an oil seal constructed inaccordance with the invention, showing the seal in position on theshaft;

Fig. 2 is an end View of the seal; and

Figs. 3 and 4 are -radial sections through two modied seal structures.

The seal shown in Figs. l and 2 of the drawing consists of a centrallyapertured sheet metal cup I0, a molded composition packing ring II andan endless coil spring I2. The packing ring II is characterized by aradially extending iiange I3 and an axially extending sealing portionIt. The ange I3 is bonded or otherwise secured inv any suitable mannerto the bottom I5 of the cup.

The sealing portion I4 is provided about its inner periphery with atapering surface I 8 which terminates in a sharp sealing lip Il forengagement with the shaft I8 or other member to be sealed, and isprovided about its outer periphery with an annular groove I9. The grooveI9 is located with itsV center in substantially the same plane as thesealing lip Il, whereby to cause the spring to exert its greatestpressure against the packing ring at the location of the lip. The springI2 is applied under tension to the groove I9 and is held in place by ashoulder 20 which forms one side of the'groove. From the sealing lip Ilthe packing ring preferably extends radially straight out a shortdistance, presenting an abrupt end face 2I close to the shaft. f In themodicat-ion shown in Fig. 3 the sealing lip 22 of the packing ring iswidened somewhat, the packing ring is cut back at 23 to increase theiiexibiiity of the sealing portion 24 as a whole, the radially extendingflange 25 of the packing ring is molded about inturned tongues 26 struckfrom the bottom 2l of the cup. and the packing ring is extended-axiallyat the outer periphery of the ange 25 in bonded engagement with the rim28 of the cup.

In the modification shown in Fig. 4 the tapering surface 29 of theaxially extending portion 30 of the sealing ring is covered with africtionreducing band 3i of exible fabric material, the end face 32 ofthe packing ring is uniformly tapered from the sealing lip 33 out to thespringretaining shoulder 3d, and the radially extending ange 35 of thepacking ring is additionally secured to the bottom 33 ci the cup bysmall tongues 3l which extend into the packing from the bottom of thecup, iirst in one direction and then in another.

I claim:

l. In an oil seal, an annular packing having a solid sealing portion ofinteriorly tapered form for engagement at its small diameter end with acylindrical surface on a shaft or other member to be sealed, saidpacking being provided with a spring-retaining shoulder on its outersurface adjacent the small diameter end of the taper, and an endlesscoil spring encircling the sealing portion of the packing in engagementwith the shoulder for pressing the sealing portion against thecylindrical surface on the shaft or other member to be sealed, thesealing portion of the packing at the small diameter end of the taperbeing undercut back to approximately the me dian plane of the spring tolocate the sealing lip in the plane of greatest pressure and provide anon-sealing portion in substantially the plane of said shoulder.

2. In an oil seal, an annular packing having a solid sealing portion ofinteriorly tapered form for engagement at its Vsmall diameter end with acylindrical surface on a shaft or other member to be sealed, saidpacking being provided with a spring-retaining groove in its outersurface adjacent the small diameter end of the taper, and an endlesscoil spring seated in the groove for pressing the sealing portion of thepacking against the cylindrical surface on the shaft or other member tobe sealed, the sealing portion of the packing at the small diameter endof the taper being undercut back to approximately the median plane ofthe spring to locate the sealing lip in the plane oi greatest pressureand pro= jacent the small diameter end of the taper, and an endless coilspring encircling the sealing portion of the packing in engagement withthe shoulder for prsing the sealing portion against the shaft or othermember to be sealed. the seaiing portion of tlie packing at thesmalldiameter end oi' the taper being undercut back to approximately themedian plane of the spring to locate the sealing lip in the plane ofgreatest pressure.

' PHELPs wmnm

